1. Field of the Invention
The present invention relates to electric appliances for household or community use, intended for the preparation and treatment of food products in liquid, pasty or solid form, of the mixer/blender, juicer, grinder, kneader, vegetable-cutter, grater, ice-cube breaker type and other like devices, comprising a work tool driven by an electric motor for rotating at the bottom of a vat or bowl closed by a removable lid.
2. History of Related Art
Such appliances are known to be generally equipped with a safety device adapted to avoid any risk of untimely contact of the user's fingers with the work tool while the latter is being driven in rotation. Such a safety device most often employs a contactor connected to the supply circuit of the drive motor, which contactor is arranged to prevent any passage of current in the direction of the motor when the lid is not correctly seated to the vat or bowl.
Document FR-A-2 587 592 (SANTOS) describes a juicer apparatus for preparing fruit or vegetable juice, provided with a safety device which has proved to be of particularly high-performance. This device comprises, in combination:
locking means abutting on the lid to urge it against the edge of the upper opening of the bowl;
an immobilizing mechanism arranged to act elastically on the shaft of the electric motor to prevent rotation thereof;
an electrical contactor which is connected to the supply circuit of the said motor and which tends elastically to maintain the circuit open;
and a cam whose manual rotation effects actuation of the means for locking the lid, releases the immobilizing mechanism and controls closure of the contactor.
In fact, the locking means are formed by two vertical rods diametrally opposite each other with respect to the vat. One of the ends of each of these rods is flared in order to abut against a lateral lug of the lid, while the opposite end carried a ring engaged on a horizontal shaft adapted to move transversely under the effect of rotation of the cam.
It will be readily understood that such an arrangement necessarily involves a precise indexing of the removable lid whose positioning on the open upper part of the vat employs combined movements. The system is therefore not easily acceptable for appliances other than juicers, necessitating frequent fillings and emptyings. Due to the symmetry imposed by the two locking rods, the parts constituting tile safety device must be produced and mounted with precision, particularly concerning tile positioning of the control cam.
Finally, this device, particularly advantageous in the case of a juicer, has proved to be difficult to transpose to an apparatus of different structure, more particularly, mixer/blenders for household or community use.
It is a particular object of tile present invention to overcome this drawback and to further improve the guarantee of reliability of the safety device.